Just picked up the Buick transmission and have noticed the tail shaft housing will have to be changed. I'm assuming the wires on the back that come off it for the speed sensor (??) on the driver's side, and which come off my Suburban trans on the passenger side, will require the swap because they look totally different even though the wires might reach around and plug in (not sure about that, even). Also noticed the Buick transmission does not have the black control box on the driver's side that my Sub has, and has a metal U shaped piece bolted to a shaft which will probably have to come off so the black box off the sub trans can be bolted on. I don't have the Sub trans out yet, so may notice some other externals that are a bit different, but I have been told by 2 transmission repair shops these will interchange (eventually). Just posting this to help anyone who might search for the same kind of info since I have had no luck on the forums getting a definitive answer.